本文旨在研究地下經濟規模與金融發展對實質人均GDP成長率之影響。我們使用二種不同金融發展資料，分別為私部門信貸規模及股市成交值規模。使用的資料型式為追蹤資料，時間由西元1981年至2008年，國家共22個，其中有14個已開發國家，8個開發中國家。模型部分共採用三種型式，首先為一般線性模型，其次為納入地下經濟規模與金融發展交互作用之非線性模型，最後則是門檻迴歸模型。 結果顯示，在一般線性模型中，地下經濟規模及私部門信貸規模對實質人均GDP成長率的影響並不顯著，而股市成交值規模對實質人均GDP成長率有顯著正面影響。 而在納入地下經濟規模與金融發展之交互作用項後，私部門信貸規模與地下經濟規模的交互作用項對實質人均GDP成長率有顯著負面影響，而股市成交值規模與地下經濟規模之交互作用項對實質人均GDP成長率有負面影響，但不顯著。由上面的結果，我們推斷地下經濟規模與實質人均GDP成長率可能存在著非線性的關係。 在門檻迴歸中，若把顯著水準設在10%，我們發現納入私部門信貸規模與股市成交值規模的模型存在顯著的門檻效果。在門檻迴歸中，若把私部門信貸規模或是股市成交值規模當作門檻變數，當金融發展程度低時，地下經濟規模對實質人均GDP成長率有顯著正面影響，而當金融發展程度高時，地下經濟規模對實質人均GDP成長率的影響並不顯著。 總結來說，我們建議低度金融發展國家適度的允許地下部門發展，因為政府無法干預地下部門，因此地下部門的營運較有效率，適度允許反而有助於提高資本投資的效率，進而促進實質人均GDP成長率。相反地，我們建議高度金融發展國家的政府應限制地下部門的發展。 / This paper focuses on linear effects and nonlinear effects of underground economy and financial development on the growth rate of real GDP per capita. Utilizing two alternative measures of financial development, including the size of private credit and stock trade. The analysis relies on a sample of 22 countries for the period 1981-2008, including 14 developed countries and 8 developing countries. We use three different models, including linear model, nonlinear regression with a cross-term and panel threshold model. The results show that in the linear model, underground economy and private credit have no significant impact on the growth rate of real GDP per capita, but stock trade has a significant positive impact on the growth rate of real GDP per capita. Moreover, the interaction between private credit and underground economy has a significant negative impact on the growth rate of real GDP per capita, on the other hand, the interaction between stock trade and underground economy has an insignificant negative impact on the growth rate of real GDP per capita. Hence, we speculate there have a nonlinear effect between underground economy and the growth rate of real GDP per capita. In the panel threshold model, if the level of significance is set in 10%, we find that the model with private credit and stock trade have threshold effect, it implies that the sample can be split into two regimes: High degree of financial development and Low degree of financial development. Underground economy has a significant positive impact on the growth rate of real GDP per capita when private credit is low, so does stock trade. In conclusion, we suggest that it may be optimal for countries with a less developed formal financial sector to accept more tax evasion, because it accelerates the efficiency in capital investment and then facilates the growth rate of real GDP per capita. On the contrary, countries with a more developed formal financial sector should impose more tax compliance.

大額支付系統係銀行間清算之重要金融基礎設施，除可降低整體商業與金融交易成本外，並作為中央銀行傳遞貨幣政策操作效果之管道，我國大額支付系統成交值為國內生產毛額之數倍，且逐年增加，說明大額支付系統之於經濟活動的重要性，但大額支付系統成交值與國內生產毛額之間是否具有同向變動的關係，少有相關實證研究。 大額支付系統具有促進貨幣交易媒介之功能，透過貨幣所得流通速率（Income Velocity of Money）影響貨幣需求，並與中央銀行貨幣政策公開市場操作密切相關，本研究由總體經濟因素、中央銀行貨幣政策因素、支付系統制度性與結構性因素及重大事件等建立迴歸分析模型，探討各解釋變數與大額支付系統成交值變動之關聯性。實證結果發現，名目國內生產毛額、通貨比率及持有貨幣的機會成本、新臺幣兌美元匯率、全體銀行法定準備金、中央銀行定期存單淨釋出金額及大額支付系統週轉率等解釋變數，均與大額支付系統成交值變動具有正向之統計顯著性，顯示大額支付系統與相關總體經濟因素有關。 大額支付系統伴隨一國經濟成長、支持相關經濟活動，且與中央銀行貨幣政策操作有關，具中央銀行傳遞貨幣政策操作效果之功能，此外，本研究發現，大額支付系統週轉率與大額支付系統成交值變動呈正向相關，中央銀行藉由提升大額支付系統效率措施，促使貨幣需求減少，進而降低貨幣供給，應有助於降低貨幣發行成本。 / Large value payment system (LVPS) is an important financial infrastructure for interbank clearing, which can reduce the overall business and financial transaction costs, and could help transmitting the central bank’s monetary policy effect to the market. Taiwan's LVPS transaction value increasing yearly is several times of its GDP. It shows the importance of the LVPS to domestic economic activities. There is little empirical research about the relationship between the LVPS transaction value and GDP. The LVPS could promote the function of the medium of exchange, which affects the demand of money through the Income Velocity of Money and is closely related to the central bank monetary policy. This study’s regression analysis is based on the macro economic factors, the central bank monetary policy factors, payment system institutional and structural factors and major events. The empirical results show that the GDP, the currency ratio and the opportunity cost of holding the currency, USD/NTD exchange rate, the reserve of the whole bank, the net central bank's negotiable certificates of deposit and LVPS turnover, those variables have positive relationship and statistically significant with the LVPS transaction value changes. The LVPS is accompanied by the economic growth of a nation, supporting the relevant economic activities, related to the central bank's monetary policy, and served as the conduit of the monetary policy effect. The study also found that LVPS turnover and its transaction value’s changes are positively related. The central bank would decrease the cost of money issuance by introducing some institutional measures to strengthen the efficiency of the LVPS, then could help reducing the money demand and supply.

第一章 台灣與美國股市價量關係的分量迴歸分析 摘要 本文利用分量迴歸來觀察台灣和美國股市報酬率和成交量的價量關係。實證結果發現兩地股市的價量關係截然不同。台灣股市的報酬率與成交量之間具有正向關係，呈現「價量齊揚」和「價跌量縮」的現象，而前者效果通常較顯著；但報酬率接近最大漲幅限制時，報酬率與成交量之間並無顯著關係，報酬率接近最大跌幅限制時，「價跌量縮」的現象甚至更強。相對於台灣，美國股市的報酬率與成交量則出現「價量齊揚」與「價量背離」互相對稱的 “V” 字關係。就實證方法而言，傳統以 OLS 方法估計的迴歸模型並無法得到上述的實證結果。進一步的分析顯示，融券成數的高低以及平盤以下不得放空等規定都是造成台灣股市出現「價跌量縮」的可能原因。 第二章 股市價量關係的分量迴歸分析 (二) 摘要 本章利用分量迴歸觀察包括台灣在內的亞洲新興工業國家與成熟股市的價量關係。實證結果顯示，亞洲新興工業國家和日本股市「價量齊揚」的效果較強，其中香港、南韓和新加坡呈現較弱的「價量背離」現象，因此價量之間有不對稱的 “V” 字關係；而日本股市則呈現「價跌量縮」，與第一章分析的台灣股市價量關係相似。在成熟股市的價量關係中，英國金融時報指數、美國道瓊工業指數和德國股價指數皆呈現對稱的 “V” 字關係，與美國US指數的價量關係相似。亞洲地區的國家在1997下半年到1998上半年普遍經歷了一場金融風暴，本文進一步的分析發現在這場風暴期間，亞洲地區除了台灣以外，日本、香港、南韓與新加坡都出現較強的「價量齊揚」與「價量背離」，這種現象可能肇因於投資人認為風暴期間的股價報酬率風險較高，遂使得股價報酬率對成交量的反應較為敏銳。相對而言，歐美地區的國家，受到亞洲金融風暴的影響較小，所以整體的價量關係在亞洲金融風暴期間並無重大改變。本章的結果都是透過分量迴歸所獲得。 第三章 股市價量因果關係的分量迴歸分析 摘要 本文依據分量迴歸設計 Granger 因果關係的新檢驗方法，並依此方法來檢驗幾個股市價量之間的因果關係。本文分析的股市包括日本、英國與美國等世界前三大股市，以及合稱亞洲四小龍的台灣、香港、南韓與新加坡等新興工業國家或地區的股市。實證結果顯示：除了台灣股市以外，其他的股市皆呈現 “V” 字的跨期價量關係。其中英國、美國、香港和新加坡股市的跨期價量關係大體呈現正向「價量齊揚」與負向「價量背離」互相對稱的 “V” 字關係，而日本和南韓股市則是「價量齊揚」較強的不對稱 “V” 字關係。此一結果表示這些股市的價量之間都存在分配上的 Granger (1969) 因果關係。但若以均數迴歸來衡量跨期價量關係，則所有股市都呈現不顯著的跨期價量關係，也就是傳統文獻上所謂價量之間沒有 Granger 因果關係。本文所提出的 Granger 因果關係之分量迴歸分析，可以觀察到整個條件分配中各分量的因果關係，為分配上的 Granger 因果關係提供一個較完整的檢驗方法。 / We examine the relationship between the stock return and trading volume in the Taiwan and U.S. Stock Exchanges using quantile regression. The empirical results show that the return-volume relations in these two exchanges are quite different. For Taiwan data, there are significant positive return-volume relations across quantiles, showing that a large positive return is usually accompanied with a large trading volume and a large negative return with a small trading volume, yet the effect of former is stronger. However, such relations change when returns approach the price limits. We also find that for U.S. data, return-volume relations exhibit symmetric V-shapes across quantiles, showing that a large return (in either sign) is usually accompanied with a large trading volume. On the other hand, linear regressions estimated by the ordinary least square method are unable to reveal such patterns. Further investigation shows that various restrictions on short sales in the Taiwan Stock Exchange may explain the difference between the return-volume relations in Taiwan and U.S. data.